1. Field of the Invention
The present invention relates to a navigation apparatus for and a navigation method of searching for a route from a place of departure to a destination.
2. Description of Related Art
When users set a destination, prior art navigation apparatuses can search for a route from a place of departure to the destination and display the route on a display. However, because the route searching cannot be carried out for an area in the vicinity of the destination when a road leading to the destination has a zone that is closed to vehicles, for example, prior art navigation apparatuses have no alternative but to search for a route from the place of departure to a place located forward of the destination, and then display the route on the display.
Such dispensing of information to users is insufficient so that users cannot finally recognize a desired route to the destination from the on-screen route from the place of departure to a place located forward of the destination. Japanese patent application publication (TOKKAIHEI) No. 11-23301 discloses a navigation apparatus that, when the navigation apparatus cannot carry out the route searching for an area in the vicinity of the destination, notifies users of the fact that the route searching cannot be carried out for an area in the vicinity of the destination in order to complement the insufficient dispensing of information to users.
A problem encountered with prior art navigation apparatuses constructed as mentioned above is that although, when determining that they cannot carry out the route searching for an area in the vicinity of the destination, notifies users of the fact that the route searching cannot be carried out for an area in the vicinity of the destination, users cannot know the reason why the route searching cannot be carried out for an area in the vicinity of the destination even if they are notified of the fact at a time of departure. When taking a distance drive for a long time, for example, some users might forget the fact that the route searching cannot be carried out for an area in the vicinity of the destination. In such a case, the route guidance can be stopped suddenly before the vehicle reaches the destination, and this results in creating confusion for users.
The present invention is proposed to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a navigation apparatus and a navigation method capable of surely notifying users that the route searching cannot be carried out for an area in the vicinity of a destination, and making users recognize the fact that the route guidance will be stopped before a vehicle that uses the navigation apparatus or the navigation method reaches the destination.
In accordance with an aspect of the present invention, there is provided a navigation apparatus including a notification unit for, in a case where a route searching unit cannot carry out route searching for an area in the vicinity of a destination, notifying users that the route searching unit cannot carry out route searching for the area in the vicinity of the destination when a physical quantity associated with a relationship between the current position of a vehicle determined by a current position determination unit and the destination is less than a preset reference value.
As a result, the navigation apparatus can make users recognize the fact that route guidance will be stopped before the vehicle reaches the destination.
In accordance with another aspect of the present invention, there is provided a navigation method including the step of, in a case where route searching cannot be carried out for an area in the vicinity of a destination, notifying users that route searching cannot be carried out for the area in the vicinity of the destination when a physical quantity associated with a relationship between the current position of a vehicle and the destination is less than a preset reference value.
As a result, the navigation method can make users recognize the fact that route guidance will be stopped before the vehicle reaches the destination.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.